As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
TRIP NR 1117761 CREW NOTED A GRINDING NOISE AND BURNING SMELL WHEN SELECTING THE NR 2 ACM. SYSTEM WAS TURNED OFF AND THE AIRCRAFT CONTINUED TO THE DESTINATION. SYSTEM WAS MEL`D AND AIRCRAFT WAS MOVED WHERE MAINTENANCE CONFIRMED THE GRINDING NOISE WAS ORIGINATING FROM THE NR 2 ACM. MAINTENANCE REPLACED THE NR 2 ACM UNIT.